Hi @Members_YBFuVgZ ,
Wi-Fi calling is a feature offered by the network provider. At the moment, there is no way to set this by default on Android 13. However, it may be on the feature if this get integrated by the providers. Keep an eye out!
Some networks let you pick WiFi preferred, most don't. 
@Members_YBFuVgZ
On Fold4 international model, F936B D/S, on stock Samsung Android 13 firmware for U.K. and on the EE network, Wi-Fi preferred is in...
Phone dialler app > Menu (3 dots, top right) > Settings (see screenshot)
Hi! Many thanks - really useful. I have the identical model but on SMARTY but see the below. I can only toggle on and off and clicking on the button (rather than toggle) only toggles on and off as well. This implies it's a provider option which is interesting - I'll see what SMARTY say but must admit previous contacts with them has been friendly but the agents had limited technical knowledge e.g. last time they told me to remove the SIM and rub the contacts and then blamed contention for it not working (bizarre since going through wifi!!)
